Light-emitting element

ABSTRACT

Disclosed is a light emitting device. The light emitting device includes a first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, a second conductive semiconductor layer on the active layer, a passivation layer surrounding the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer, a first light extracting structure layer having a concave-convex structure on the passivation layer, a first electrode layer electrically connected to the first conductive semiconductor layer through the passivation layer and the first light extracting structure layer, and a second electrode layer electrically connected to the second conductive semiconductor layer through the passivation layer and the light extracting structure layer.

TECHNICAL FIELD

The embodiment relates to a light emitting device.

BACKGROUND ART

Recently, a light emitting diode (LED) is spotlighted as a lightemitting device. Since the LED can convert electric energy into lightenergy with high efficiency and long life span of about 5 years or more,the LED can remarkably reduce the energy consumption and repair andmaintenance cost. In this regard, the LED is spotlighted in thenext-generation lighting field.

Such an LED is prepared as a light emitting semiconductor layerincluding a first conductive semiconductor layer, an active layer and asecond conductive semiconductor layer, in which the active layergenerates light according to current applied thereto through the firstand second conductive semiconductor layers.

Meanwhile, since a material constituting the light emittingsemiconductor layer has a refractive index lower than that of externalair, light generated from the active layer is not effectively emitted tothe outside, but totally reflected from a boundary surface andextinguished at an inside of the light emitting semiconductor layer.

To solve this problem, a concave-convex light extracting structure isformed on the first conductive semiconductor layer or the secondconductive semiconductor layer provided at one side of the active layer.However, the electrical characteristics of the LED may be degraded dueto the light extracting structure.

DISCLOSURE Technical Problem

The embodiment provides a light emitting device having a novel structureand a method of manufacturing the same.

The embodiment provides a light emitting device capable of improving theelectrical characteristic and light extraction efficiency and a methodof manufacturing the same.

Technical Solution

According to the embodiment, a light emitting device includes a firstconductive semiconductor layer, an active layer on the first conductivesemiconductor layer, a second conductive semiconductor layer on theactive layer, a passivation layer surrounding the first conductivesemiconductor layer, the active layer, and the second conductivesemiconductor layer, a first light extracting structure layer having aconcave-convex structure on the passivation layer, a first electrodelayer electrically connected to the first conductive semiconductor layerthrough the passivation layer and the first light extracting structurelayer, and a second electrode layer electrically connected to the secondconductive semiconductor layer through the passivation layer and thelight extracting structure layer.

According to the embodiment, the light emitting device includes asupport substrate, a second conductive semiconductor layer on thesupport substrate, an active layer on the second conductivesemiconductor layer, a first conductive semiconductor layer on theactive layer, a passivation layer surrounding the second conductivesemiconductor layer, the active layer, and the first conductivesemiconductor layer, a light extracting structure layer having aconcave-convex structure on the passivation layer, and a first electrodelayer formed on the first conductive semiconductor layer through thepassivation layer and the light extracting structure layer.

ADVANTAGEOUS EFFECTS

The embodiment can provide a light emitting device having a novelstructure and a method of manufacturing the same.

The embodiment can provide a light emitting device capable of improvingthe electrical characteristic and light extraction efficiency and amethod of manufacturing the same.

DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view showing a light emitting device according toa first embodiment;

FIG. 2 is a sectional view showing a light emitting device according toa second embodiment;

FIG. 3 is a sectional view showing a light emitting device according toa third embodiment;

FIG. 4 is a sectional view showing a light emitting device according toa fourth embodiment; and

FIG. 5 is a view showing a light emitting device according to a fifthembodiment.

BEST MODE Mode for Invention

In the description of the embodiments, it will be understood that, whena layer (or film), a region, a pattern, or a structure is referred to asbeing “on” or “under” another substrate, another layer (or film),another region, another pad, or another pattern, it can be “directly” or“indirectly” on the other substrate, layer (or film), region, pad, orpattern, or one or more intervening layers may also be present. Such aposition of the layer has been described with reference to the drawings.

The thickness and size of each layer shown in the drawings may beexaggerated, omitted or schematically drawn for the purpose ofconvenience or clarity. In addition, the size of elements does notutterly reflect an actual size.

FIG. 1 is a sectional view showing a light emitting device according tothe first embodiment.

Referring to FIG. 1, a buffer layer 201 is formed on a growth substrate10, and a light emitting semiconductor layer including a firstconductive semiconductor layer 20, an active layer 30, and a secondconductive semiconductor layer 40 is formed on the buffer layer 201.

The light emitting semiconductor layer is partially removed through MESAetching, and a first current spreading layer 502 is formed on the firstconductive semiconductor layer 20 exposed through the MESA etching. Inaddition, a second current spreading layer 501 is formed on a secondconductive semiconductor layer 40.

A passivation layer 80 surrounds the light emitting semiconductor layerand the first and second current spreading layers 502 and 501, and afirst light extracting structure layer 90 having a concave-convexstructure 90 a is formed on the passivation layer 80.

Then, the first light extracting structure layer 90 and the passivationlayer 80 are selectively removed, so that first and second electrodelayers 70 and 60 are formed on the first and second current spreadinglayers 502 and 501, respectively.

In addition, a reflective layer 100 is formed below the growth substrate10.

In more detail, for example, the growth substrate 10 may include one ofAl₂O₃, SiC, Si, AlN, GaN, AlGaN, glass and GaAs.

Before the first conductive semiconductor layer 20 is grown, the bufferlayer 201 is formed on the growth substrate 10. For instance, the bufferlayer 201 may include at least one of InGaN, AlN, SiC, SiCN, and GaN.

The light emitting semiconductor layer including the first conductivesemiconductor layer 20, the active layer 30, and the second conductivesemiconductor layer 40 may include group-III nitride-based semiconductormaterials. For example, the first conductive semiconductor layer 20 mayinclude a gallium nitride layer including n type impurities such as Si,and the second conductive semiconductor layer 40 may include a galliumnitride layer including p type impurities such as Mg or Zn. In addition,the active layer 30, which generates light through the recombination ofelectrons and holes, may include one of InGaN, AlGaN, GaN, and AlInGaN.The wavelength of light emitted from the light emitting device isdetermined according to the type of materials constituting the activelayer 30.

The active layer 30 and the second conductive semiconductor layer 40 areformed on a part of the first conductive semiconductor layer 20. Inother words, the part of the first conductive semiconductor layer 20makes contact with the active layer 30.

Although not shown, an interface modification layer may be furtherformed on the second conductive semiconductor layer 40.

The interface modification layer may include a superlattice structure,one of InGaN, GaN, AlInN, AlN, InN, and AlGaN doped with firstconductive impurities, one of InGaN, GaN, AlInN, AlN, InN, and AlGaNdoped with second conductive impurities, or one of group IIInitride-based elements having nitrogen-polar surfaces. In particular,the interface modification layer having the superlattice structure mayinclude a nitride or a carbon nitride including group II, III, or IVelements.

The first current spreading layer 502 is partially formed on the firstconductive semiconductor layer 20, and the second current spreadinglayer 501 is partially or wholly formed on the second conductivesemiconductor layer 40.

Both of the first and second current spreading layers 502 and 501 maynot be necessarily required. That is, at least one of the first andsecond current spreading layers 502 and 501 may be omitted.

The first and second current spreading layers 502 and 501 can beprepared as a single layer structure or a multi-layer structureincluding at least one selected from the group consisting of ITO (indiumtin oxide), doped ZnO (doped Zinc oxide), TiN (titanium nitride), IZO(indium zinc oxide), IZTO (indium zinc tin oxide), NiO (nickel oxide),RuO₂ (ruthenium oxide), IrO₂ (iridium oxide), doped In₂O₃ (doped indiumoxide), Au, Ag, doped SnO₂ (doped tin oxide), GITO (gallium indium tinoxide), PdO (palladium oxide), PtO (platinum oxide), Ag₂O (silveroxide), and doped TiO₂ (doped titanium oxide).

The first and second current spreading layers 502 and 501 uniformlyspread current applied to the first and second conductive semiconductorlayers 20 and 40, thereby improving light emitting efficiency. Inaddition, the first and second current spreading layers 502 and 501allow the first and second electrode layers 70 and 60 to be sufficientlybonded to the first and second conductive semiconductor layers 20 and40, respectively.

The passivation layer 80 is formed on the light emitting semiconductorlayer including the first and second current spreading layers 502 and501 except for some portions of the first and second current spreadinglayers 502 and 501. The passivation layer 80 prevents the light emittingdevice from being physically, chemically, or electrically damaged.

The passivation layer 80 includes a transparent electric insulatingmaterial. For example, the passivation layer 80 includes at least one ofSiO₂ (silicon dioxide), SiN_(x) (silicon nitride), MgF₂ (magnesiumfluoride), Cr₂O₃ (chromium oxide), Al₂O₃ (aluminum oxide), TiO₂, ZnS(zinc sulfide), ZnO (zinc oxide), CaF₂ (calcium fluoride), AlN (aluminumnitride), and CrN (chromium nitride).

The first light extracting structure layer 90 is provided on thepassivation layer 80. The first light extracting structure layer 90 isselectively removed such that portions of the first and second currentspreading layers 502 and 510 are exposed similarly to the passivationlayer 80.

The first light extracting structure layer 90 may include a materialhaving high light transmissivity and can be prepared as a surfacematerial layer having a negative polarity such that the concave-convexstructure 90 a such as a cylindrical structure or a conical structurecan be formed on the surface of the first light extracting structurelayer 90 through CVD (Chemical Vapor Deposition) and PVD (Physical VaporDeposition) or a wet etching process using an acid/base solution.

For example, the first light extracting structure layer 90 may includegroup II-VI compounds including ZnO or MgZnO, or group III-V compoundsincluding GaN or AlN. The first light extracting structure layer 90 mayinclude hexagonal crystalline material. In addition, the first lightextracting structure layer 90 may include TiO₂ or Al₂O₃.

The first light extracting structure layer 90 is provided on thepassivation layer 80 to improve light extraction efficiency whilepreventing the electrical characteristic of the light emittingsemiconductor layer from being degraded.

The first electrode layer 70 is formed on a part of the first currentspreading layer 502. If the first current spreading layer 502 isomitted, the first electrode layer 70 may make contact with the firstconductive semiconductor layer 20.

In order to form an interface having a superior adhesive property withrespect to the first conductive semiconductor layer 20 or the firstcurrent spreading layer 502, the first electrode layer 70 may include amaterial forming an ohmic contact interface with respect to the firstconductive semiconductor layer 20 or the first current spreading layer502. For example, the first electrode layer 70 may include one selectedfrom the group consisting of Ti, Al, Cr, V, Au, and Nb. In addition, thefirst electrode layer 70 can be formed by using silicide.

The second electrode layer 60 is formed on a part of the second currentspreading layer 501.

The second electrode layer 60 may include a material forming aninterface representing a superior adhesive property or a schottkycontact interface representing a superior adhesive property with respectto the second current spreading layer 501. For example, the secondelectrode layer 60 may include at least one selected from the groupconsisting of Ni, Al, Cr, Cu, Pt, Au, Pd, ITO, ZnO, ZITO, TiN, and IZO.In addition, the second electrode layer 60 can be formed by usingsilicide.

The reflective layer 100 is formed below the growth substrate 10, andincludes a material having a high reflective rate. For example, thereflective layer 100 may include at least one of Ag, Al, Rh, Pd, Ni, Au,a DBR (Distributed Bragg Reflector), and an ODR (Omni-DirectionalReflector).

The reflective layer 100 reflects light directed downward beyond thegrowth substrate 10, so that the light emitting efficiency of the lightemitting device can be improved.

FIG. 2 is a sectional view showing a light emitting device according toa second embodiment.

The light emitting device according to the second embodiment has thestructure similar to that of the light emitting device according to thefirst embodiment. Therefore, the following description will be focusedon the difference from the light emitting device according to the firstembodiment in order to avoid redundancy.

Referring to FIG. 2, the buffer layer 201 is formed on the growthsubstrate 10, and the light emitting semiconductor layer including thefirst conductive semiconductor layer 20, the active layer 30, and thesecond conductive semiconductor layer 40 is formed on the buffer layer201.

The light emitting semiconductor layer is partially removed through aMESA etching process, and the first current spreading layer 502 isformed on the first conductive semiconductor layer 20 exposed throughthe MESA etching process. In addition, the second current spreadinglayer 501 is formed on the second conductive semiconductor layer 40.

The passivation layer 80 surrounds the light emitting semiconductorlayer and the first and second current spreading layers 502 and 501, andthe first light extracting structure layer 90 having the concave-convexstructure 90 a is formed on the passivation layer 80.

Then, the first light extracting structure layer 90 and the passivationlayer 80 are selectively removed, so that the first and second electrodelayers 70 and 60 are formed on the first and second current spreadinglayers 502 and 501, respectively.

A second light extracting structure layer 110 and the reflective layer100 which have concave-convex structures 110 a are formed below thegrowth substrate 10.

The second light extracting structure layer 110 allows light directeddownward beyond the growth substrate 10 to be extracted to thereflective layer 100 so that the reflective rate of light in thereflective layer 100 can be improved.

The second light extraction layer 110 may include a material having highlight transmissivity and include a surface material layer having anegative polarity such that the concave-convex structure 110 a such as acylindrical structure or a conical structure can be formed on thesurface of the second light extraction layer 110 through CVD (ChemicalVapor Deposition) and PVD (Physical Vapor Deposition) or a wet etchingprocess using an acid/base solution.

For example, the second light extracting structure layer 110 may includegroup II-VI compounds including ZnO or MgZnO, or group III-V compoundsincluding GaN or AlN. The second light extracting structure layer 110may include hexagonal crystalline material. In addition, the secondlight extracting structure layer 110 may include TiO₂ or Al₂O₃.

The second light extracting structure layer 110 is provided below thegrowth substrate 10 to improve light extraction efficiency whilepreventing the electrical characteristic of the light emittingsemiconductor layer from being degraded.

FIG. 3 is a view showing a light emitting device according to a thirdembodiment.

The light emitting device according to the third embodiment has thestructure similar to that of the light emitting device according to thefirst embodiment. Therefore, the following description will be focusedon the difference from the light emitting device according to the firstembodiment in order to avoid redundancy.

Referring to FIG. 3, the buffer layer 201 is formed on the growthsubstrate 10, and the light emitting semiconductor layer including thefirst conductive semiconductor layer 20, the active layer 30, and thesecond conductive semiconductor layer 40 is formed on the buffer layer201.

The light emitting semiconductor layer is partially removed through aMESA etching process, and the first current spreading layer 502 isformed on the first conductive semiconductor layer 20 exposed throughthe MESA etching process. In addition, the second current spreadinglayer 501 is formed on the second conductive semiconductor layer 40.

The passivation layer 80 surrounds the light emitting semiconductorlayer and the first and second current spreading layers 502 and 501, andthe first light extracting structure layer 90 having the concave-convexstructure 90 a is formed on the passivation layer 80.

Then, the first light extracting structure layer 90 and the passivationlayer 80 are selectively removed, so that the first and second electrodelayers 70 and 60 are formed on the first and second current spreadinglayers 502 and 501, respectively.

The reflective layer 100 is formed on portions of the first electrodelayer 70 and the first light extracting structure layer 90, and onportions of the second electrode layer 60 and the first light extractingstructure layer 90.

The reflective layer 100 may include an electrical conductive materialto electrically connect the first and second electrode layers 70 and 60to the outside.

The reflective layer 100 allows the light from the active layer 30 to beemitted to the outside through the growth substrate 10. In other words,different from the light emitting device according to the first andsecond embodiments, the light emitting device according to the thirdembodiment emits the light from the active layer 30 to the outsidemainly through the growth substrate 10.

FIG. 4 is a view showing a light emitting device according to the fourthembodiment.

The light emitting device according to the fourth embodiment has thestructure similar to that of the light emitting device according to thethird embodiment. Therefore, the following description will focused onthe difference from the light emitting device according to the thirdembodiment in order to avoid redundancy.

Referring to FIG. 4, the buffer layer 201 is formed on the growthsubstrate 10, and the light emitting semiconductor layer including thefirst conductive semiconductor layer 20, the active layer 30, and thesecond conductive semiconductor layer 40 is formed on the buffer layer201.

The light emitting semiconductor layer is partially removed through aMESA etching process, and the first current spreading layer 502 isformed on the first conductive semiconductor layer 20 exposed throughthe MESA etching process. In addition, the second current spreadinglayer 501 is formed on the second conductive semiconductor layer 40.

The passivation layer 80 surrounds the light emitting semiconductorlayer and the first and second current spreading layers 502 and 501, andthe first light extracting structure layer 90 having the concave-convexstructure 90 a is formed on the passivation layer 80.

Then, the first light extracting structure layer 90 and the passivationlayer 80 are selectively removed, so that the first and second electrodelayers 70 and 60 are formed on the first and second current spreadinglayers 502 and 501, respectively.

The reflective layer 100 is formed on portions of the first electrodelayer 70 and the first light extracting structure layer 90, and onportions of the second-electrode layer 60 and the first light extractingstructure layer 90.

The reflective layer 100 may include an electrical conductive materialto electrically connect the first and second electrode layers 70 and 60to the outside.

The reflective layer 100 allows the light from the active layer 30 to beemitted to the outside through the growth substrate 10. In other words,different from the light emitting device according to the first andsecond embodiments, the light emitting device according to the fourthembodiment emits the light from the active layer 30 to the outsidemainly through the growth substrate 10.

The second light extracting structure layer 110 having theconcave-convex structure 110 a is formed below the growth substrate 10.The second light extracting structure layer 110 allows light directeddownward beyond the growth substrate 10 to be effectively extracted tothe outside.

The second light extraction layer 110 may include a material having highlight transmissivity and include a surface material layer having anegative polarity such that the concave-convex structure 110 a such as acylindrical structure or a conical structure can be formed on thesurface of the second light extraction layer 110 through CVD (ChemicalVapor Deposition) and PVD (Physical Vapor Deposition) or a wet etchingprocess using an acid/base solution.

For example, the second light extracting structure layer 110 may includegroup II-VI compounds including ZnO or MgZnO, or group III-V compoundsincluding GaN or AlN. The light extracting structure 110 may includehexagonal crystalline material. In addition, the second light extractingstructure layer 110 may include TiO₂ or Al₂O₃.

The second light extracting structure layer 110 is provided below thegrowth substrate 10 to improve light extraction efficiency whilepreventing the electrical characteristic of the light emittingsemiconductor layer from being degraded.

FIG. 5 is a view showing a light emitting device according to a fifthembodiment.

Different from the light emitting devices according to the first tofourth embodiments, the light emitting device according to the fifthembodiment includes a vertical type light emitting device to which thetechnical spirit of the present disclosure is applied as an example.

Referring to FIG. 5, a reflective ohmic contact current spreading layer130 is formed on a support substrate 150, and the light emittingsemiconductor layer including the first conductive semiconductor layer20, the active layer 30, and the second conductive semiconductor layer40 is formed on the reflective ohmic contact current spreading layer130. In addition, a protrusion part 140 is formed on the firstconductive semiconductor layer 20 to improve light extractionefficiency.

The passivation layer 80 surrounding the light emitting semiconductorlayer is formed on top and lateral surfaces of the light emittingsemiconductor layer, and the first light extracting structure layer 90having the concave-convex structure 90 a is formed on the passivationlayer 80.

The passivation layer 80 and the light extracting structure layer 90 areselectively removed to expose a portion of the first conductivesemiconductor layer 20, and the first electrode layer 70 is formed onthe first conductive semiconductor layer 20.

Then, the second electrode layer 60 is formed below the supportsubstrate 150.

In more detail, the support substrate 150, which is an electricconductive layer, may include a wafer substrate including at least oneof Si, SiGe, ZnO, GaN, AlSiC, and GaAs, or may include metal, alloy, orsolid solution including at least one of Cu, Ni, Ag, Al, Nb, Ta, Ti, Au,Pd, and W.

The support substrate 150 has the shape of a sheet, a disk, or a foil ata thickness in the range of about 5 μm to 1 mm. The support substrate150 may be formed through an electro-plating scheme, a PVD scheme, or aCVD scheme.

The reflective ohmic contact current spreading layer 130 may include Ag,alloy containing Ag, solid solution containing Ag, Rh, alloy containingRh, solid solution containing Rh, Al, alloy containing Al, solidsolution containing Al, Pt, alloy containing Pt, solid solutioncontaining Pt, Pd, alloy containing Pd, solid solution containing Pd,Au, alloy containing Au, solid solution containing Au, Ni, alloycontaining Ni, solid solution containing Ni, or silicide such as Ag—Si,Rh—Si, Pd—Si, Ni—Si, Cr—Si, or Pt—Si.

The surface of the reflective ohmic contact current spreading layer 130facing the support substrate 150 may include at least one of Ag, Au, Ni,Ti, and Cu providing a superior adhesive property.

The light emitting semiconductor layer including the first conductivesemiconductor layer 20, the active layer 30, and the second conductivesemiconductor layer 40 may include group-III nitride-based semiconductormaterials. For example, the first conductive semiconductor layer 20 mayinclude a gallium nitride layer including n type impurities such as Si,and the second conductive semiconductor layer 40 may include a galliumnitride layer including p type impurities such as Mg or Zn. In addition,the active layer 30, which generates light through the recombination ofelectrons and holes, may include one of InGaN, AlGaN, GaN, and AlInGaN.The wavelength of light emitted from the light emitting device isdetermined according to the type of materials constituting the activelayer 30.

The protrusion part 140 may include a material identical to or differentfrom that of the first conductive semiconductor layer 20. The protrusionpart 140 may have an irregular pattern through a wet etching process, ormay have a regular pattern through a lithography process.

The passivation layer 80 surrounds the light emitting semiconductorlayer except for a region for the first electrode layer 70. Thepassivation layer 80 prevents the light emitting device from beingphysically, chemically, or electrically damaged.

The passivation layer 80 includes a transparent electric insulatingmaterial. For example, the passivation layer 80 includes at least one ofSiO₂, SiN_(x), MgF₂, Cr₂O₃, Al₂O₃, TiO₂, ZnS, ZnO, CaF_(z), AlN, andCrN.

The second light extraction layer 110 may include a material having highlight transmissivity and include a surface material layer having anegative polarity such that the concave-convex structure 110 a such as acylindrical structure or a conical structure can be formed on thesurface of the second light extraction layer 110 through CVD (ChemicalVapor Deposition) and PVD (Physical Vapor Deposition) or a wet etchingprocess using an acid/base solution.

For example, the light extracting structure layer 90 may include groupII-VI compounds including ZnO or MgZnO, or group III-V compoundsincluding GaN or AlN. The light extracting structure layer 90 mayinclude hexagonal crystalline material. In addition, the lightextracting structure layer 90 may include TiO₂ or Al₂O₃.

The first light extracting structure layer 90 is provided on thepassivation layer 80 to improve light extraction efficiency whilepreventing the electrical characteristic of the light emittingsemiconductor layer from being degraded.

The first electrode layer 70 is formed on a portion of the firstconductive semiconductor layer 20. In order to form an interfacerepresenting a superior adhesive property with respect to the firstconductive semiconductor layer 20, the first electrode layer 70 mayinclude a material forming an ohmic contact interface with respect tothe first conductive semiconductor layer 20. For example, the firstelectrode layer 70 may include one of Ti, Al, Cr, V, Ag, Rh, Au, Pd, andNb.

The second electrode layer 60 is formed below the support substrate 60.

The second electrode layer 60 may include a material forming aninterface having a superior adhesive property and an ohmic contactinterface with respect to the support substrate 60. For example, thesecond electrode layer 60 may include at least one selected from thegroup consisting of Ni, Al, Cr, Cu, Ag, Al, Rh, Pt, Au, and Pd.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure.

INDUSTRIAL APPLICABILITY

The embodiment is applicable to a light emitting device used as a lightsource.

1. A light emitting device comprising: a first conductive semiconductorlayer; an active layer on the first conductive semiconductor layer; asecond conductive semiconductor layer on the active layer; a passivationlayer surrounding the first conductive semiconductor layer, the activelayer, and the second conductive semiconductor layer; a first lightextracting structure layer having a concave-convex structure on thepassivation layer; a first electrode layer electrically connected to thefirst conductive semiconductor layer through the passivation layer andthe first light extracting structure layer; and a second electrode layerelectrically connected to the second conductive semiconductor layerthrough the passivation layer and the light extracting structure layer.2. The light emitting device of claim 1, further comprising a growthsubstrate under the first conductive semiconductor layer.
 3. The lightemitting device of claim 2, further comprising a reflective layer underthe growth substrate.
 4. The light emitting device of claim 3, furthercomprising a second light extracting structure layer having aconcave-convex structure between the growth substrate and the reflectivelayer.
 5. The light emitting device of claim 1, further comprising afirst current spreading layer electrically connected to the firstelectrode on the first conductive semiconductor layer.
 6. The lightemitting device of claim 1, further comprising a second currentspreading layer electrically connected to the second electrode layer onthe second conductive semiconductor layer.
 7. The light emitting deviceof claim 1, further comprising a reflective layer separately formed onthe first electrode layer and the first light extracting structurelayer, and on the second electrode layer and the first light extractingstructure layer.
 8. The light emitting device of claim 7, furthercomprising: a growth substrate under the first conductive semiconductorlayer; and a second light extracting structure layer having aconcave-convex structure under the growth substrate.
 9. The lightemitting device of claim 1, wherein the first light extracting structurelayer includes one of group II-VI compounds including ZnO or MgZnO,group III-V compounds including GaN or AlN, TiO₂ and Al₂O₃.
 10. A lightemitting device comprising: a support substrate; a second conductivesemiconductor layer on the support substrate; an active layer on thesecond conductive semiconductor layer; a first conductive semiconductorlayer on the active layer; a passivation layer surrounding the secondconductive semiconductor layer, the active layer, and the firstconductive semiconductor layer; a light extracting structure layerhaving a concave-convex structure on the passivation layer; and a firstelectrode layer formed on the first conductive semiconductor layerthrough the passivation layer and the light extracting structure layer.11. The light emitting device of claim 10, further comprising areflective ohmic contact current spreading layer between the supportsubstrate and the second conductive semiconductor layer.
 12. The lightemitting device of claim 11, wherein the reflective ohmic contactcurrent spreading layer includes one selected from the group consistingof Ag, alloy containing Ag, solid solution containing Ag, Rh, alloycontaining Rh, solid solution containing Rh, Al, alloy containing Al,solid solution containing Al, Pt, alloy containing Pt, solid solutioncontaining Pt, Pd, alloy containing Pd, solid solution containing Pd,Au, alloy containing Au, solid solution containing Au, Ni, alloycontaining Ni, solid solution containing Ni, Ag—Si, Rh—Si, Pd—Si, Ni—Si,Cr—Si, and Pt—Si.
 13. The light emitting device of claim 10, furthercomprising a protrusion part on the first conductive semiconductorlayer.
 14. The light emitting device of claim 10, further comprising asecond electrode layer under the growth substrate.
 15. The lightemitting device of claim 10, wherein the first light extractingstructure layer includes one of group II-VI compounds including ZnO orMgZnO, group III-V compounds including GaN or AlN, TiO₂ and Al₂O₃.